Machine-center and the like.



w. eozmz. mcums CENTER AND THE LIKE.

APPLICATION FILED MAYIQ.

Patented Sept. 24, 1918.

U TED STATES PATENT ()FFIGE,

WILLIAM GOERTZ, 0F BROOKLYN, NEW YORK.

MACHINE-CENTER AND THE LIKE.

Specification of Letters Patent.

Patented Sept. 24, 1918.

Application filed may 19, 1916. Serial N0. 98,530.

To all whom it may camera:

Be it known that I, WILLIAM Gonn'rz, a

citizen of the United States, residing at machines which embody spindleswhich engage the pieces to be worked, at points'lying within the axes ofsaid spindles. ore specific objects of invention will appear in thespecification and be pointed out in the appended claim reference beinghad to the accompanying drawings which show a preferred embodiment ofmy. invention.

In the drawings Figure 1 is a combined side elevation and axial sectionof a machine center embodying my improvements;

Fig. 2 is a transverse section on the line 22, Fig. 1. ,7

In the art to which the present invention -'appertains, it has long beencustomary to make lathe centers of machinery steel, some- 7 times casevhardened to enable it to better withstand hard wear, or of tempered toolsteel which possesses higher wearing qualities. In modern machine shoppractice, it has become imperative to employ hlgh speeds to largework-as well as small. One of the developments of these requirements hasbeen the so-called high-speed steels which embody certain ingredientsincluding tungsten, and which are extremely tough. Such steels aremoreover very e ensive. When a piece of machinery steel is casehardenedor a piece of tool steel is hardened and tempered, it is liable tobecome warped,

even when proper care is exercised in the o eration. This defectlispeculiarly undeslrable in ta ered bodies although it may be overcome yan expensive grinding oper- 'to the taper of the center core.

ation. According to my invention,however, an outer tapered body portion1 is provided With an axial bore or hollow which extends for aconsiderable part of the length of said body portion. Said central boreis adapted to receive a' core 2. which preferably fits therein with adriving fit and which may be provided with a flat inner end to abutsquarely against the flat inner end of the bore in the body portion 1.The outer end of the core 2 isprovided with a conical point 3 forconstituting the efiective work-supporting machine center. If desired,the outer body portion 1 may be provided with a flange 4 to make iteasier to insert the center into a spindle, and to remove it therefrom.The outer end of said body portion may be conically tapered at 5 tocorrespond It will be understood-that my construction makes it possibleto construct the outer tapered body of relatively soft stock whichrequires neither case hardening nor tempering while permitting theessential wear resisting part of the center to be made of a relativelysmall piece of stock of uniform cross-section which may be morejreadilymanipulated for hardening, tempering and grinding, requires no taper,and which especially in the'case of the so-called high speed steelsinvolves a great saving in the first cost of production.

I claim A machine center or the like, comprising anouter tapered body ofmachinery steel provided with a cylindrical hollow extending a portionof its length, and a cylindrical bar of high speed steel abutting at oneend against the inner end of said hollow and having its other endprojecting, the projecting end of said cylindrical bar and thecircum-adj acent portions of the outer body portion bein provided withan unbroken surface suitaily formed to provide a work-con tering point.w

. WILLIAM GOERTZ.

